1. Field of the Invention
This invention relates to an image scanning apparatus for two-dimensionally scanning an image recording material by a light beam. This invention particularly relates to an image scanning apparatus wherein scanning in the main scanning direction is conducted by moving a light detecting means and/or a light emitting means supported on an endless moveable member and scanning in the sub-scanning direction is conducted by moving the recording material.
2. Description of the Prior Art
An image scanning method for recording an image on a recording material or for reading out an image therefrom by two-dimensionally scanning the recording material by a light beam is widely used in facsimile devices and the like. In the method, two-dimensional scanning is conducted by deflecting a light beam by a light deflector in one direction (main scanning direction) to form a scanning line on the recording material and by mechanically moving the recording material in a direction (sub-scanning direction) normal to the main scanning direction, thereby forming many scanning lines in parallel with each other.
In the apparatus for carrying out image scanning, since the light deflector is positioned far away from the recording material for deflection of the light beam, the apparatus naturally becomes large. When image read-out is conducted by use of a light beam, in order to prevent attenuation of light reflected by the recording material or light emitted by a stimulable phosphor sheet upon stimulation thereof in the case where the stimulable phosphor sheet as described, for example, in U.S. Pat. No. 4,387,428 and Japanese Unexamined Patent Publication No. 56 (1981)-11395 is used as the recording material, a sheet-like light guide member is positioned close to the recording material. Also in this case, the apparatus becomes large since the light guide member has to have a large size and a complicated shape for guiding light entering from a long linear light input face thereof up to a small photodetector. Further, when the light guide member is of a complicated shape, the distance from the light input face thereof to the photodetector becomes nonuniform, and nonuniformity of light detection sensitivity arises.